intel_pstate: Refactor driver to support CPUs with different MSR layouts

Non-core processors have a different MSR layout to commumicate P state
information. Refactor the driver to use CPU dependent accessors to
P state information.

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 98 insertions, 46 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index d57648989c0b..6b37c9ff1d64 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -78,7 +78,6 @@ struct cpudata {
 
         struct timer_list timer;
 
-        struct pstate_adjust_policy *pstate_policy;
         struct pstate_data pstate;
         struct _pid pid;
 
@@ -100,15 +99,21 @@ struct pstate_adjust_policy {
         int i_gain_pct;
 };
 
-static struct pstate_adjust_policy default_policy = {
-        .sample_rate_ms = 10,
-        .deadband = 0,
-        .setpoint = 97,
-        .p_gain_pct = 20,
-        .d_gain_pct = 0,
-        .i_gain_pct = 0,
+struct pstate_funcs {
+        int (*get_max)(void);
+        int (*get_min)(void);
+        int (*get_turbo)(void);
+        void (*set)(int pstate);
 };
 
+struct cpu_defaults {
+        struct pstate_adjust_policy pid_policy;
+        struct pstate_funcs funcs;
+};
+
+static struct pstate_adjust_policy pid_params;
+static struct pstate_funcs pstate_funcs;
+
 struct perf_limits {
         int no_turbo;
         int max_perf_pct;
@@ -186,14 +191,14 @@ static signed int pid_calc(struct _pid *pid, int busy)
 
 static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
 {
-        pid_p_gain_set(&cpu->pid, cpu->pstate_policy->p_gain_pct);
-        pid_d_gain_set(&cpu->pid, cpu->pstate_policy->d_gain_pct);
-        pid_i_gain_set(&cpu->pid, cpu->pstate_policy->i_gain_pct);
+        pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
+        pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
+        pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
 
         pid_reset(&cpu->pid,
-                cpu->pstate_policy->setpoint,
+                pid_params.setpoint,
                 100,
-                cpu->pstate_policy->deadband,
+                pid_params.deadband,
                 0);
 }
 
@@ -227,12 +232,12 @@ struct pid_param {
 };
 
 static struct pid_param pid_files[] = {
-        {"sample_rate_ms", &default_policy.sample_rate_ms},
-        {"d_gain_pct", &default_policy.d_gain_pct},
-        {"i_gain_pct", &default_policy.i_gain_pct},
-        {"deadband", &default_policy.deadband},
-        {"setpoint", &default_policy.setpoint},
-        {"p_gain_pct", &default_policy.p_gain_pct},
+        {"sample_rate_ms", &pid_params.sample_rate_ms},
+        {"d_gain_pct", &pid_params.d_gain_pct},
+        {"i_gain_pct", &pid_params.i_gain_pct},
+        {"deadband", &pid_params.deadband},
+        {"setpoint", &pid_params.setpoint},
+        {"p_gain_pct", &pid_params.p_gain_pct},
         {NULL, NULL}
 };
 
@@ -337,33 +342,60 @@ static void intel_pstate_sysfs_expose_params(void)
 }
 
 /************************** sysfs end ************************/
-
-static int intel_pstate_min_pstate(void)
+static int core_get_min_pstate(void)
 {
         u64 value;
         rdmsrl(MSR_PLATFORM_INFO, value);
         return (value >> 40) & 0xFF;
 }
 
-static int intel_pstate_max_pstate(void)
+static int core_get_max_pstate(void)
 {
         u64 value;
         rdmsrl(MSR_PLATFORM_INFO, value);
         return (value >> 8) & 0xFF;
 }
 
-static int intel_pstate_turbo_pstate(void)
+static int core_get_turbo_pstate(void)
 {
         u64 value;
         int nont, ret;
         rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
-        nont = intel_pstate_max_pstate();
+        nont = core_get_max_pstate();
         ret = ((value) & 255);
         if (ret <= nont)
                 ret = nont;
         return ret;
 }
 
+static void core_set_pstate(int pstate)
+{
+        u64 val;
+
+        val = pstate << 8;
+        if (limits.no_turbo)
+                val |= (u64)1 << 32;
+
+        wrmsrl(MSR_IA32_PERF_CTL, val);
+}
+
+static struct cpu_defaults core_params = {
+        .pid_policy = {
+                .sample_rate_ms = 10,
+                .deadband = 0,
+                .setpoint = 97,
+                .p_gain_pct = 20,
+                .d_gain_pct = 0,
+                .i_gain_pct = 0,
+        },
+        .funcs = {
+                .get_max = core_get_max_pstate,
+                .get_min = core_get_min_pstate,
+                .get_turbo = core_get_turbo_pstate,
+                .set = core_set_pstate,
+        },
+};
+
 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 {
         int max_perf = cpu->pstate.turbo_pstate;
@@ -383,7 +415,6 @@ static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
 {
         int max_perf, min_perf;
-        u64 val;
 
         intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
 
@@ -395,11 +426,8 @@ static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
         trace_cpu_frequency(pstate * 100000, cpu->cpu);
 
         cpu->pstate.current_pstate = pstate;
-        val = pstate << 8;
-        if (limits.no_turbo)
-                val |= (u64)1 << 32;
 
-        wrmsrl(MSR_IA32_PERF_CTL, val);
+        pstate_funcs.set(pstate);
 }
 
 static inline void intel_pstate_pstate_increase(struct cpudata *cpu, int steps)
@@ -421,9 +449,9 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 {
         sprintf(cpu->name, "Intel 2nd generation core");
 
-        cpu->pstate.min_pstate = intel_pstate_min_pstate();
-        cpu->pstate.max_pstate = intel_pstate_max_pstate();
-        cpu->pstate.turbo_pstate = intel_pstate_turbo_pstate();
+        cpu->pstate.min_pstate = pstate_funcs.get_min();
+        cpu->pstate.max_pstate = pstate_funcs.get_max();
+        cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
 
         /*
          * goto max pstate so we don't slow up boot if we are built-in if we are
@@ -464,7 +492,7 @@ static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 {
         int sample_time, delay;
 
-        sample_time = cpu->pstate_policy->sample_rate_ms;
+        sample_time = pid_params.sample_rate_ms;
         delay = msecs_to_jiffies(sample_time);
         mod_timer_pinned(&cpu->timer, jiffies + delay);
 }
@@ -523,14 +551,14 @@ static void intel_pstate_timer_func(unsigned long __data)
         { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&policy }
 
 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
-        ICPU(0x2a, default_policy),
-        ICPU(0x2d, default_policy),
-        ICPU(0x3a, default_policy),
-        ICPU(0x3c, default_policy),
-        ICPU(0x3e, default_policy),
-        ICPU(0x3f, default_policy),
-        ICPU(0x45, default_policy),
-        ICPU(0x46, default_policy),
+        ICPU(0x2a, core_params),
+        ICPU(0x2d, core_params),
+        ICPU(0x3a, core_params),
+        ICPU(0x3c, core_params),
+        ICPU(0x3e, core_params),
+        ICPU(0x3f, core_params),
+        ICPU(0x45, core_params),
+        ICPU(0x46, core_params),
         {}
 };
 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
@@ -554,8 +582,7 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
         intel_pstate_get_cpu_pstates(cpu);
 
         cpu->cpu = cpunum;
-        cpu->pstate_policy =
-                (struct pstate_adjust_policy *)id->driver_data;
+
         init_timer_deferrable(&cpu->timer);
         cpu->timer.function = intel_pstate_timer_func;
         cpu->timer.data =
@@ -683,9 +710,9 @@ static int intel_pstate_msrs_not_valid(void)
         rdmsrl(MSR_IA32_APERF, aperf);
         rdmsrl(MSR_IA32_MPERF, mperf);
 
-        if (!intel_pstate_min_pstate() ||
-                !intel_pstate_max_pstate() ||
-                !intel_pstate_turbo_pstate())
+        if (!pstate_funcs.get_max() ||
+                !pstate_funcs.get_min() ||
+                !pstate_funcs.get_turbo())
                 return -ENODEV;
 
         rdmsrl(MSR_IA32_APERF, tmp);
@@ -698,10 +725,30 @@ static int intel_pstate_msrs_not_valid(void)
 
         return 0;
 }
+
+void copy_pid_params(struct pstate_adjust_policy *policy)
+{
+        pid_params.sample_rate_ms = policy->sample_rate_ms;
+        pid_params.p_gain_pct = policy->p_gain_pct;
+        pid_params.i_gain_pct = policy->i_gain_pct;
+        pid_params.d_gain_pct = policy->d_gain_pct;
+        pid_params.deadband = policy->deadband;
+        pid_params.setpoint = policy->setpoint;
+}
+
+void copy_cpu_funcs(struct pstate_funcs *funcs)
+{
+        pstate_funcs.get_max   = funcs->get_max;
+        pstate_funcs.get_min   = funcs->get_min;
+        pstate_funcs.get_turbo = funcs->get_turbo;
+        pstate_funcs.set       = funcs->set;
+}
+
 static int __init intel_pstate_init(void)
 {
         int cpu, rc = 0;
         const struct x86_cpu_id *id;
+        struct cpu_defaults *cpu_info;
 
         if (no_load)
                 return -ENODEV;
@@ -710,6 +757,11 @@ static int __init intel_pstate_init(void)
         if (!id)
                 return -ENODEV;
 
+        cpu_info = (struct cpu_defaults *)id->driver_data;
+
+        copy_pid_params(&cpu_info->pid_policy);
+        copy_cpu_funcs(&cpu_info->funcs);
+
         if (intel_pstate_msrs_not_valid())
                 return -ENODEV;